In his book The Design of Everyday Things, Donald Norman defines affordances as follows:
Affordances provide strong clues to the operations of things. Plates are for pushing. Knobs are for turning. Slots are for inserting things into. Balls are for throwing or bouncing. When affordances are taken advantage of, the user knows what to do just by looking:
no picture, label, or instruction is required. Complex things may require explanation, but simple things should not. When simple things need pictures, labels, or instructions, the design has failed.
—The Design of Everyday Things, MIT Press, 1998 We recommend this excellent book for anyone with an interest in design, although the section on the affordances of doors may ruin your interactions with buildings because you will encounter examples of poorly thought-out design almost daily.
As adoption of the Internet of Things gathers pace, more and more of our cities, homes, and environment will become suffused with technology.
With these additional behaviours and capabilities will come additional
38 Designing the Internet of Things
complexity—something that successful designers of connected devices and services will need to counter.
By their very nature, many of the new capabilities bestowed upon objects will be hidden from sight or not immediately apparent from first glance, which makes intuitive design difficult. What are the affordances of digitally enhanced objects?
How do we convey to the user of an object that it can communicate with the cloud? Or that this device is capable of short-range communication such as RFID? What does it mean that a toy knows what the temperature is or when it is shaken? How do you know whether your local bus shelter is watching you or, possibly more importantly, why?
An important start is to keep the existing affordances of the object being enhanced. Users who don’t realise that a device has any extra capabilities should still be able to use it as if it hasn’t. Although this principle sounds like common sense, it is often discarded due to costs or difficulties in design.
For example, a “dumb” light dimmer switch is usually implemented as a rotary knob which gives the user fine-grained control over the brightness.
When it is hooked up to a home-automation system, the difficulties of synchronising the state of both the knob and the light level, now that the brightness can be controlled remotely or automatically, often leads to the knob being replaced with a couple of buttons. As a result, the user loses the ability to make both rapid large changes and smaller, fine-grained adjust- ments. A better approach would be to adopt the system used on many stereo systems where the volume knob is a motorized potentiometer; the user can still adjust it in the conventional manner, and any changes made by the remote are instantly reflected in the position of the volume knob.
Things get trickier with interactions that are invisible—either because they use wireless communication or because they are invoked through learned gestures. However, we can still design the physical form of the object to encourage the right behaviour. Nothing inherent in RFID requires it to be laid out flat in a card, but this leads users towards the correct interaction of tapping their Oyster transport payment card onto the similarly flat reader surface when travelling on the London Underground.
Similar rules apply when designing physical interfaces. Don’t overload familiar connectors with unfamiliar behaviours. For example, you shouldn’t use 3.5mm audio jacks to provide power, although alternative “data-level”
Chapter 2: Design Principles for Connected Devices 39
uses are probably okay. And if you’re designing a new connector completely, think about ways to prevent users from connecting it the wrong way round.
littleBits (http://littlebits.cc/about) faced this problem when they were designing their modular, plug-together electronic circuit building blocks. They were looking for a way to make it easy and relatively foolproof to connect things together because the product is aimed at beginners. Their solution is a nice approach in this respect, using magnets to both discourage incorrect connection whilst also encouraging the correct connection.
SUMMARY
This chapter will have given you a deeper understanding of the emerging field of the Internet of Things and some ways to direct your thinking when you are designing something to fit into the landscape.
The examples have shown how you need to think not just about the techni- cal details of how the device will work, but also of how it will fit into the wider context of the user’s life. Unlike an app on her phone, your Internet of Things product will take up physical space in the world and won’t be silenced just by the user’s focusing on a different app, so you need to consider that for her.
You also need to take care not to divulge any information that users wouldn’t expect you to. It is a new field full of expanding possibilities which gives us opportunities for delighting and enriching people’s lives, but we need to do so in a way that doesn’t scare or alienate the less technical in the population.
Careful use of touchpoints such as magic and fairytales can help with this, as will systems which fail gracefully and still perform their non-computer- enhanced functions in the way to which everyone is accustomed.
Even this early in the book you will already have encountered different aspects of the network bleeding through—for example, in the description of Natalie Jeremijenko’s Live Wire or the mention of HTTP protocol versions in the section on graceful degradation.
That’s hardly surprising in a book about the Internet of Things, but we don’t assume that you have a full understanding of how the network works or exactly what it can do. The next chapter looks at the common protocols on the Internet (and even what a protocol is) and how they interrelate, to give you a better understanding of how the Internet works.